1. Field of the Invention
The described technology relates generally to an organic light emitting display and a manufacturing method thereof capable of improving an aperture ratio.
2. Description of the Related Art
Among flat panel displays, an organic light emitting display is a self light emitting type of display that electrically excites an organic compound that emits light.
Since the organic light emitting display does not require a backlight as with a liquid crystal display, the organic light emitting display can become thin and light, and a manufacturing process of the organic light emitting display can be simplified. Further, the organic light emitting display can be fabricated at low temperature, have a high-speed response speed of 1 ms or less, and show characteristics such as low power consumption, wide viewing angle, and high contrast.
The organic light emitting display includes an organic emission layer between an anode and a cathode. Therefore, holes supplied from the anode and electrons supplied from the cathode are coupled to each other in the organic emission layer to form an exciton that is an electron-hole pair, causing the organic light emitting display to emit light by energy generated upon the exciton being restored to a ground state.
Generally, the organic light emitting display is manufactured by forming thin film transistors and an organic light emitting diode electrically connected with the thin film transistors on a substrate and thereafter, bonding the substrate to a sealing substrate.
The organic light emitting display manufactured as above operates as any one of a top emission type or a bottom emission type. The bottom emission type has a more stable diode than the top emission type, but has a lower aperture ratio than the top emission type.
The bottom emission type includes a light emitting area in addition to a transistor area, a capacitor area, and a wire area. Among them, only when the capacitor has a predetermined capacity or more, the capacitor may maintain signal data of one frame and may be compensated. However, it is difficult to decrease the size of the capacitor which occupies a large area.
Further, thinning the capacitor causes a short-circuit defect rate and a process distribution increase.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology, and therefore it may contain information that does not constitute prior art as per 35 U.S.C. §102.